Riconfigurare i territori metroplitani. Forme di urbanizzazione e fenomeni di pressione insediativa sui sistemi di interesse naturale in Sicilia

The consumption of the soil due to urbanization it is a phenomena already for many years under observations, but of which only the scientific environment has noticed the elevated environmental impact progress. From a disciplinary point of view, is possible to identify a line of research focusing on the analysis and identification of new morphologies of urbanization and on the interaction among different settlement patterns coexisting in a specific context. This reading complements with the scientific production about the forms of settlement pressure on environmental systems, producing change and deterioration on natural ecosystems and loss of biodiversity. A necessary reference for this line are the studies about fragmentation processes (linear, concentrated, mixed) and those about the seclusion of natural and semi-natural habitats (protected or unprotected. Such references combine with the analyses conducted on the process of replacement of natural systems with artificial ecomosaics. The state of urbanization in Sicily is interested by the phenomenon of urban sprawling which, starting from the seventies, have strongly contributed to shape the regional territory both from the physical and from the functional point of view. Such phenomenon has mainly affected the fringe areas around the metropolitan areas where land consumed by low density settlements amounts to 42% of the entire urbanized territory; such percentage, when considered for coastal municipalities, reaches above the 75% of the urbanized territory. In the case of natural systems, human pressure phenomena weight on an already critical situation, given by a spotted distribution of protected areas. The level of fragmentation and isolation of these areas risks to become worse. In Sicily, the absence of the environment assessment tools and the disconnection between urban and regional planning and sector planning have determined an inadequate level of control of human pressure on environmental systems. Regarding this general framework, this paper presents a clarification and a reformulation of the reciprocity relationship between built environment and open territory, with the aim of identifying possible strategies to manage the phenomena of urban sprawl in the metropolitan context, a main objective of European territorial policies and of many national policies of the member states.